发表机构
Visvesvaraya National Institute of Technology, Nagpur（印度纳格浦尔维斯韦萨瓦亚国家理工学院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究在$f(T)$遥平行引力中引入广义Chaplygin气体，通过解析哈勃参数并利用CC与Pantheon数据拟合，验证了该模型能解释从减速到加速的转变，且与暗能量行为及宇宙年龄观测一致。
AI 中文摘要
本文研究了基于函数 $f(T)=\beta(-T)^{1/2}+\gamma(-T)$ 的修正引力框架下的宇宙动力学，其中 $T$ 表示挠率标量。物质部分采用广义Chaplygin气体（GCG）建模，其状态方程为 $p=-\frac{\mathcal{A}}{\rho^{\eta}}$，使得该模型能够描述从早期类物质阶段到晚期加速宇宙的演化过程。通过推导哈勃参数 $H(z)$ 的解析表达式，我们采用基于 $\chi^{2}$ 最小化方法的贝叶斯统计技术，利用宇宙计时器（CC）以及联合（CC+Pantheon）观测数据集进行参数估计。减速参数表现出从减速到加速的转变，而其当前值表明当前正处于加速膨胀阶段。该模型给出的当前状态方程参数与暗能量行为一致，同时能量条件表明NEC和DEC得到满足，而SEC在晚期被违反。$\omega-\omega'$ 平面显示出冻结型quintessence行为，趋近于 $\Lambda$CDM类点 $(\omega,\omega')=(-1,0)$，而宇宙学图景分析为宇宙膨胀的演化提供了额外见解。估算的宇宙年龄也与当前观测界限一致。这些结果表明，在 $f(T)$ 遥平行引力框架下的GCG情景为解释晚期宇宙加速膨胀提供了一个可行且与观测一致的框架。
英文摘要
In this paper, we investigate the cosmological dynamics of a modified gravity framework based on the function $f(T)=β(-T)^{1/2}+γ(-T)$, where $T$ denotes the torsion scalar. The matter sector is modeled using the Generalized Chaplygin Gas (GCG) with the equation of state $p=-\frac{\mathcal{A}}{ρ^η}$, allowing the model to describe the evolution from an early-time matter-like phase to a late-time accelerated universe. By deriving an analytical expression for the Hubble parameter $H(z)$, we perform parameter estimation using Bayesian statistical techniques based on the $χ^{2}$-minimization method with the Cosmic Chronometer (CC) and joint (CC+Pantheon) observational datasets. The deceleration parameter exhibits a transition from deceleration to acceleration, while the present-day value indicates the current accelerated expansion. The model yields a present-day EoS parameter consistent with dark-energy-like behavior, while the energy conditions indicate that the NEC and DEC are satisfied and the SEC is violated at late times. The $ω-ω'$ plane shows a freezing quintessence behavior, approaching the $Λ$CDM-like point $(ω,ω')=(-1,0)$, while the cosmographic analysis offers additional insight into the evolution of the cosmic expansion. The estimated age of the universe is also consistent with current observational bounds. These results demonstrate that the GCG scenario within $f(T)$ teleparallel gravity provides a viable and observationally consistent framework for explaining the late-time accelerated expansion of the universe.
